271 lines
7.4 KiB
C
271 lines
7.4 KiB
C
/*
|
|
* Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
|
|
* Copyright 2005-2006 Ian Kent <raven@themaw.net>
|
|
*
|
|
* This file is part of the Linux kernel and is made available under
|
|
* the terms of the GNU General Public License, version 2, or at your
|
|
* option, any later version, incorporated herein by reference.
|
|
*/
|
|
|
|
/* Internal header file for autofs */
|
|
|
|
#include <linux/auto_fs.h>
|
|
#include <linux/auto_dev-ioctl.h>
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/time.h>
|
|
#include <linux/string.h>
|
|
#include <linux/wait.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/sched/signal.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/namei.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/list.h>
|
|
#include <linux/completion.h>
|
|
#include <linux/file.h>
|
|
#include <linux/magic.h>
|
|
|
|
/* This is the range of ioctl() numbers we claim as ours */
|
|
#define AUTOFS_IOC_FIRST AUTOFS_IOC_READY
|
|
#define AUTOFS_IOC_COUNT 32
|
|
|
|
#define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION)
|
|
#define AUTOFS_DEV_IOCTL_IOC_COUNT \
|
|
(AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD - AUTOFS_DEV_IOCTL_VERSION_CMD)
|
|
|
|
#ifdef pr_fmt
|
|
#undef pr_fmt
|
|
#endif
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ":pid:%d:%s: " fmt, current->pid, __func__
|
|
|
|
/*
|
|
* Unified info structure. This is pointed to by both the dentry and
|
|
* inode structures. Each file in the filesystem has an instance of this
|
|
* structure. It holds a reference to the dentry, so dentries are never
|
|
* flushed while the file exists. All name lookups are dealt with at the
|
|
* dentry level, although the filesystem can interfere in the validation
|
|
* process. Readdir is implemented by traversing the dentry lists.
|
|
*/
|
|
struct autofs_info {
|
|
struct dentry *dentry;
|
|
struct inode *inode;
|
|
|
|
int flags;
|
|
|
|
struct completion expire_complete;
|
|
|
|
struct list_head active;
|
|
int active_count;
|
|
|
|
struct list_head expiring;
|
|
|
|
struct autofs_sb_info *sbi;
|
|
unsigned long last_used;
|
|
atomic_t count;
|
|
|
|
kuid_t uid;
|
|
kgid_t gid;
|
|
};
|
|
|
|
#define AUTOFS_INF_EXPIRING (1<<0) /* dentry in the process of expiring */
|
|
#define AUTOFS_INF_WANT_EXPIRE (1<<1) /* the dentry is being considered
|
|
* for expiry, so RCU_walk is
|
|
* not permitted. If it progresses to
|
|
* actual expiry attempt, the flag is
|
|
* not cleared when EXPIRING is set -
|
|
* in that case it gets cleared only
|
|
* when it comes to clearing EXPIRING.
|
|
*/
|
|
#define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */
|
|
|
|
struct autofs_wait_queue {
|
|
wait_queue_head_t queue;
|
|
struct autofs_wait_queue *next;
|
|
autofs_wqt_t wait_queue_token;
|
|
/* We use the following to see what we are waiting for */
|
|
struct qstr name;
|
|
u32 dev;
|
|
u64 ino;
|
|
kuid_t uid;
|
|
kgid_t gid;
|
|
pid_t pid;
|
|
pid_t tgid;
|
|
/* This is for status reporting upon return */
|
|
int status;
|
|
unsigned int wait_ctr;
|
|
};
|
|
|
|
#define AUTOFS_SBI_MAGIC 0x6d4a556d
|
|
|
|
struct autofs_sb_info {
|
|
u32 magic;
|
|
int pipefd;
|
|
struct file *pipe;
|
|
struct pid *oz_pgrp;
|
|
int catatonic;
|
|
int version;
|
|
int sub_version;
|
|
int min_proto;
|
|
int max_proto;
|
|
unsigned long exp_timeout;
|
|
unsigned int type;
|
|
struct super_block *sb;
|
|
struct mutex wq_mutex;
|
|
struct mutex pipe_mutex;
|
|
spinlock_t fs_lock;
|
|
struct autofs_wait_queue *queues; /* Wait queue pointer */
|
|
spinlock_t lookup_lock;
|
|
struct list_head active_list;
|
|
struct list_head expiring_list;
|
|
struct rcu_head rcu;
|
|
};
|
|
|
|
static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
|
|
{
|
|
return sb->s_magic != AUTOFS_SUPER_MAGIC ?
|
|
NULL : (struct autofs_sb_info *)(sb->s_fs_info);
|
|
}
|
|
|
|
static inline struct autofs_info *autofs_dentry_ino(struct dentry *dentry)
|
|
{
|
|
return (struct autofs_info *)(dentry->d_fsdata);
|
|
}
|
|
|
|
/* autofs_oz_mode(): do we see the man behind the curtain? (The
|
|
* processes which do manipulations for us in user space sees the raw
|
|
* filesystem without "magic".)
|
|
*/
|
|
static inline int autofs_oz_mode(struct autofs_sb_info *sbi)
|
|
{
|
|
return sbi->catatonic || task_pgrp(current) == sbi->oz_pgrp;
|
|
}
|
|
|
|
struct inode *autofs_get_inode(struct super_block *, umode_t);
|
|
void autofs_free_ino(struct autofs_info *);
|
|
|
|
/* Expiration */
|
|
int is_autofs_dentry(struct dentry *);
|
|
int autofs_expire_wait(const struct path *path, int rcu_walk);
|
|
int autofs_expire_run(struct super_block *, struct vfsmount *,
|
|
struct autofs_sb_info *,
|
|
struct autofs_packet_expire __user *);
|
|
int autofs_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
|
|
struct autofs_sb_info *sbi, unsigned int how);
|
|
int autofs_expire_multi(struct super_block *, struct vfsmount *,
|
|
struct autofs_sb_info *, int __user *);
|
|
|
|
/* Device node initialization */
|
|
|
|
int autofs_dev_ioctl_init(void);
|
|
void autofs_dev_ioctl_exit(void);
|
|
|
|
/* Operations structures */
|
|
|
|
extern const struct inode_operations autofs_symlink_inode_operations;
|
|
extern const struct inode_operations autofs_dir_inode_operations;
|
|
extern const struct file_operations autofs_dir_operations;
|
|
extern const struct file_operations autofs_root_operations;
|
|
extern const struct dentry_operations autofs_dentry_operations;
|
|
|
|
/* VFS automount flags management functions */
|
|
static inline void __managed_dentry_set_managed(struct dentry *dentry)
|
|
{
|
|
dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
|
|
}
|
|
|
|
static inline void managed_dentry_set_managed(struct dentry *dentry)
|
|
{
|
|
spin_lock(&dentry->d_lock);
|
|
__managed_dentry_set_managed(dentry);
|
|
spin_unlock(&dentry->d_lock);
|
|
}
|
|
|
|
static inline void __managed_dentry_clear_managed(struct dentry *dentry)
|
|
{
|
|
dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
|
|
}
|
|
|
|
static inline void managed_dentry_clear_managed(struct dentry *dentry)
|
|
{
|
|
spin_lock(&dentry->d_lock);
|
|
__managed_dentry_clear_managed(dentry);
|
|
spin_unlock(&dentry->d_lock);
|
|
}
|
|
|
|
/* Initializing function */
|
|
|
|
int autofs_fill_super(struct super_block *, void *, int);
|
|
struct autofs_info *autofs_new_ino(struct autofs_sb_info *);
|
|
void autofs_clean_ino(struct autofs_info *);
|
|
|
|
static inline int autofs_prepare_pipe(struct file *pipe)
|
|
{
|
|
if (!(pipe->f_mode & FMODE_CAN_WRITE))
|
|
return -EINVAL;
|
|
if (!S_ISFIFO(file_inode(pipe)->i_mode))
|
|
return -EINVAL;
|
|
/* We want a packet pipe */
|
|
pipe->f_flags |= O_DIRECT;
|
|
return 0;
|
|
}
|
|
|
|
/* Queue management functions */
|
|
|
|
int autofs_wait(struct autofs_sb_info *,
|
|
const struct path *, enum autofs_notify);
|
|
int autofs_wait_release(struct autofs_sb_info *, autofs_wqt_t, int);
|
|
void autofs_catatonic_mode(struct autofs_sb_info *);
|
|
|
|
static inline u32 autofs_get_dev(struct autofs_sb_info *sbi)
|
|
{
|
|
return new_encode_dev(sbi->sb->s_dev);
|
|
}
|
|
|
|
static inline u64 autofs_get_ino(struct autofs_sb_info *sbi)
|
|
{
|
|
return d_inode(sbi->sb->s_root)->i_ino;
|
|
}
|
|
|
|
static inline void __autofs_add_expiring(struct dentry *dentry)
|
|
{
|
|
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
|
|
struct autofs_info *ino = autofs_dentry_ino(dentry);
|
|
|
|
if (ino) {
|
|
if (list_empty(&ino->expiring))
|
|
list_add(&ino->expiring, &sbi->expiring_list);
|
|
}
|
|
}
|
|
|
|
static inline void autofs_add_expiring(struct dentry *dentry)
|
|
{
|
|
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
|
|
struct autofs_info *ino = autofs_dentry_ino(dentry);
|
|
|
|
if (ino) {
|
|
spin_lock(&sbi->lookup_lock);
|
|
if (list_empty(&ino->expiring))
|
|
list_add(&ino->expiring, &sbi->expiring_list);
|
|
spin_unlock(&sbi->lookup_lock);
|
|
}
|
|
}
|
|
|
|
static inline void autofs_del_expiring(struct dentry *dentry)
|
|
{
|
|
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
|
|
struct autofs_info *ino = autofs_dentry_ino(dentry);
|
|
|
|
if (ino) {
|
|
spin_lock(&sbi->lookup_lock);
|
|
if (!list_empty(&ino->expiring))
|
|
list_del_init(&ino->expiring);
|
|
spin_unlock(&sbi->lookup_lock);
|
|
}
|
|
}
|
|
|
|
void autofs_kill_sb(struct super_block *);
|